Characterization of genes expressed during vegetative organ development in potato (Solanum tuberosum L.)

The cp rps16 cDNA encoding the chloroplast ribosomal protein S16 and a MADS-box gene cDNA, POTM1-1, were isolated and characterized in potato (Solanum tuberosum L.) to understand molecular mechanisms of plant vegetative organ development;The rps16 gene is located between the trnK gene for tRNA Lys(UUU) and trnQ gene for tRNA Gln (UUG) on the same strand in the chloroplast genome. The ribosomal binding site, 5\u27-AGGA-3\u27, is located at nucleotide position -6 to -9 from the initiation codon ATG. The coding sequence contains an 88 amino acid open reading frame (ORF) that is interrupted by an 855 bp intron. Five different inverted repeat sequences are located at the 3\u27 end. The deduced amino acid sequence of the rps16 coding sequence shows 33% homology to the E. coli ribosomal protein S16 and 95% homology to the tobacco chloroplast ribosomal protein S16. The 13 amino acids encoded by exon-1 are highly conserved (100% identity) among higher plants. Two sizes of rps16 transcripts have been identified from northern blot analysis. The 1.5 kb transcript contains the 855 bp intron and represents an unprocessed RNA molecule, whereas the 0.7 kb transcript represents the mature form. The expression of rps16 is developmentally regulated, with transcript levels decreasing during tuber development and increasing during shoot development. The potato cp rps16 gene appears to be constitutively expressed in unswollen stolons and axillary buds, and its expression is enhanced by light;A [underline]potato [underline] MADS-box gene cDNA (POTM1-1) from an early tuber cDNA library has been isolated and further characterized. The deduced amino acid sequence of POTM1-1 encodes a 250 a.a. of a putative transcription factor which contained a MADS-box domain (56 a.a.) and a K-box domain (53 a.a). The MADS-box domain shared high homology to that of flower specific homeotic proteins, TM4 of tomato (100% identity) and AP1 of Arabidopsis (92.9%). The K-box domain shared high similarity to those of TM4 (96.2% identity) and AP1 (66.0% identity). The putative secondary structure of K-box domain, however, showed an amphipathic helix-turn-helix structure that is remarkably similar to that of other plant homeotic proteins. A potential phosphorylation and four potential glycosylation sites are located in POTM1-1, suggesting that posttranslational modification processes may be involved in the activation and specificity of POTM1-1. The levels of POTM1-1 transcripts were high in leaves, roots, aerial shoot tips, underground stolon tips, and late flowers, but relatively low in stems, early flowers, and mature tubers. In the axillary-bud-tuber induction system, the levels of POTM1-1 transcripts were increased along with the shoot development, but decreased along with tuber development. We propose that POTM1-1 may function as a constitutive transcription factor that may be involved in the fundamental functions such as cell division and/or growth, or in housekeeping, or in morphologically and metabolically active tissues in all types of plant organs;Results indicated that these two genes, cp rps16 and POTM1-1, are involved in vegetative tissue development

An Affinity Propagation Clustering Algorithm for Mixed Numeric and Categorical Datasets

Clustering has been widely used in different fields of science, technology, social science, and so forth. In real world, numeric as well as categorical features are usually used to describe the data objects. Accordingly, many clustering methods can process datasets that are either numeric or categorical. Recently, algorithms that can handle the mixed data clustering problems have been developed. Affinity propagation (AP) algorithm is an exemplar-based clustering method which has demonstrated good performance on a wide variety of datasets. However, it has limitations on processing mixed datasets. In this paper, we propose a novel similarity measure for mixed type datasets and an adaptive AP clustering algorithm is proposed to cluster the mixed datasets. Several real world datasets are studied to evaluate the performance of the proposed algorithm. Comparisons with other clustering algorithms demonstrate that the proposed method works well not only on mixed datasets but also on pure numeric and categorical datasets

Top-N Recommendation on Graphs

Recommender systems play an increasingly important role in online applications to help users find what they need or prefer. Collaborative filtering algorithms that generate predictions by analyzing the user-item rating matrix perform poorly when the matrix is sparse. To alleviate this problem, this paper proposes a simple recommendation algorithm that fully exploits the similarity information among users and items and intrinsic structural information of the user-item matrix. The proposed method constructs a new representation which preserves affinity and structure information in the user-item rating matrix and then performs recommendation task. To capture proximity information about users and items, two graphs are constructed. Manifold learning idea is used to constrain the new representation to be smooth on these graphs, so as to enforce users and item proximities. Our model is formulated as a convex optimization problem, for which we need to solve the well-known Sylvester equation only. We carry out extensive empirical evaluations on six benchmark datasets to show the effectiveness of this approach.Comment: CIKM 201

A Typha Angustifolia-like MoS2/carbon nanofiber composite for high performance Li-S batteries

A Typha Angustifolia-like MoS2/carbon nanofiber composite as both a chemically trapping agent and redox conversion catalyst for lithium polysulfides has been successfully synthesized via a simple hydrothermal method. Cycling performance and coulombic efficiency have been improved significantly by applying the Typha Angustifolia-like MoS2/carbon nanofiber as the interlayer of a pure sulfur cathode, resulting in a capacity degradation of only 0.09% per cycle and a coulombic efficiency which can reach as high as 99%